JP2695267B2 - Spray drying of detergent compositions - Google Patents

Description

FIELD OF THE INVENTION The present invention relates to improved methods and apparatus for spray drying detergent slurries to form granular detergent compositions. The present invention also relates to the improved granular detergent composition that results.

[Background of the Invention]

Spray-drying large volumes (ie, thousands of pounds per hour) of a detergent slurry in a spray-drying tower is a complex operation involving many correlative factors. The correlation factors in this case are:
For example, production volume and production rate, slurry composition, operating requirements and conditions, large amount of drying air required,
And the desired physical and performance properties of the spray dried product.

As the spray tower, a spray tower provided with a single level spray nozzle near the top of the spray drying chamber has been used. Such a spray-drying method and apparatus is disclosed in US Pat. No. 2,851,097 (Ledgett, Sep. 9, 1958).

U.S. Pat.Nos. 3,629,951 and 3,629,955, both dated December 28, 1971, Davis, Hanes and Sag.
el) discloses a granular detergent composition made by an improved multi-level spray drying process and equipment.

U.S. Pat. No. 4,261,793 (Nakamura et al., Dated April 14, 1981) discloses that spray detergents are countercurrently spray-dried with uniformly spaced spray nozzles at at least two levels. It is disclosed.

U.S. Pat. No. 3,519,054 (Cavataio et al., Dated July 7, 1970) discloses a multicolor granular detergent composition made by spraying two liquid streams downward in a spray tower. . One of the two streams in this case is atomized at a level of 15-60% below the other, and this atomization is directed into the upward gas stream.

[Summary of the Invention]

It has now been found that previously known single-level and multi-level spray-drying methods are improved by carrying out specific spraying methods. That is, the spraying method is to spray at least a part (but preferably most) of the detergent slurry into a drying zone in a spray-drying tower cocurrently with air at a specific temperature and speed.

The practice of the present invention allows for increased production rates compared to conventional single-level and multi-level spray drying operations. The improvement in production speed is, for example, about 10 to 30%. From a mass production point of view, such an increase in production rate amounts to millions of pounds per year.

Surprisingly, this increase in production rate is achieved without increasing the thermal demands on the inlet air. On the contrary, the spray-drying method according to the invention improves the drying efficiency by flash-drying the particles with inlet air, which is generally colder than when the detergent slurry particles are dried by the conventional counter-current spray-drying method. And good utilization of heat. For example, according to the present invention, the temperature of the inlet air can be reduced by 10 to 15% as compared with countercurrent spray drying. The resulting particles have better physical properties (ie, the particles are crunchy, free-flowing and hard to consolidate), even in humid conditions, as compared to conventional spray-dried particles. .

The present invention also has the advantage that the bulk density of the final dry particles is easy to control. For example, it is possible to reduce the density of one composition and increase the density of another composition. Although the most often sought after in normal commercial production is to produce low density particles, the present invention is also able to increase density within a reasonable range.

The decrease in bulk density can be achieved even when the average particle size is small. Usually, the finer the spray-dried particles, the higher the bulk density. However, it is believed that the practice of the present invention will result in individual particles having low specific gravity and irregular shapes. It is presumed that these two factors combine to offset the density increases normally found in fine-grained products.

Another advantage of the present invention is that it produces less fine powder and vaporous effluent. Not only is there a small amount of fine powder (tower over) in the column effluent, but there is also the advantage that less organic (vapor) pollutants are released into the atmosphere.

Further, according to the present invention, the amount of heavy coarse material (tower tailing) is also reduced. Thus, the minimal production of fine powders and coarse particles allows the producer to increase the amount of product suitable for packaging and reduce column over and column tailing recycling.

Furthermore, according to the present invention, the above-mentioned various benefits can be obtained without increasing the amount of insoluble matter generated by the spraying operation. This insoluble material is what is believed to be formed by the physical and chemical degradation of the detergent ingredients due to the harsh drying conditions. According to the present invention, the detergent slurry is sprayed in the maximum temperature zone adjacent to the hot inlet air, which is conventionally consciously avoided in the practical spray drying method. It was unexpected that particles with good properties could be obtained.

The present invention also provides for improved spray drying of phosphate builders such as sodium tripolyphosphate. One of the limitations of spray-drying phosphate-containing detergent compositions at elevated temperatures is that overdrying converts phosphate to other undesirable phosphorus compounds such as pyrophosphate and orthophosphate. there were. According to the present invention,
This conversion is minimal.

The above-mentioned advantages of solubility and low phosphate conversion according to the invention are attributed to the overall improvement in the drying conditions employed. In this respect, a major concern in conventional drying operations is that the freshly dried particles are too dry as they fall through the tower. Usually, the highest temperature zone, that is, the region where the highest isotherm exists,
Is near the lowest area of the spray chamber. This is the point at which hot air should be sent and dispersed through the array of plenums. The heated drying gas rises countercurrently with the descending spray particles. As the atomized droplets descend in the rising air stream, they begin to dry. However, the removal of water is relatively slow in the upper region of the tower, i.e. in the warm but cold region of the tower. By the time the drop falls into the hotter area, it solidifies to become particles with a hard skin layer. It is these dry particles that still have to pass through the hot zone in the conventional manner. As a result, overdrying problems such as phosphate conversion and reduced particle solubility are prone to occur. It is also known that degradation of other heat sensitive detergent additives such as brighteners, nonionic surfactants and bactericides occurs in this area. This tends to reduce the overall performance of the detergent composition, tends to cause organic emissions, and tends to cause unpleasant color and odor problems and other aesthetic dissatisfactions.

These overdrying problems are reduced by the present invention. It is believed that when at least a portion of the clutcher slurry is cocurrently atomized with air at a particular temperature and flow rate, the time / temperature conditions experienced by the product particles are less severe. The particles are flash dried and then quickly fall out of their hot air zone. Therefore, the particles withdrawn from the base of the tower are generally cooler. In addition, the sudden release of water vapor and gases by flash drying causes the rising air flow to be changed and beneficially affected. The remaining components of the clutcher mix that are countercurrently sprayed to the higher levels of the spray tower fall at lower drying temperatures than in conventional countercurrent spray drying processes. It is believed that this provides the above advantages. As a result, according to the present invention, crisp,
A free-flowing, density-controlled, uniform particle size granular detergent composition having good solubility is obtained in high volumes. If phosphate is present in the spray dried particles, the invention also has the advantage of low phosphate conversion. Moreover, this advantage can be achieved while reducing the amount of tower effluent and increasing production.

Where the above objects and improvements are achieved by the present invention, the present invention, in an aspect of the method thereof, comprises a spray-drying tower of a large capacity of a detergent slurry comprising the steps (a) to (d) below. Is spray dried to produce a controlled density granular detergent composition while minimizing the production of dust particles and other vaporous effluents.

(A) An aqueous detergent slurry having from about 10 to 50% by weight of water and about 50 to 90% by weight of solids comprising at least one detergent surfactant or detersive builder or mixtures thereof. To prepare.

(B) The heated drying air is swirled upward in the chamber of the spray-drying tower to form a cylindrical drying zone (a) coaxial with the chamber, and Forming a low pressure concentric vortex zone (B) formed along an axis.

(C) About 30-100% by weight of the detergent slurry is continuously and directly co-flowed with air having a temperature of about 260 ° -540 ° C. and a flow rate of about 15-30 m / sec directly into a cylindrical drying zone. To spray. However, the spraying is performed by spray nozzles that are substantially evenly spaced on a plane that horizontally traverses the drying zone,
Disintegrating substantially individual sprays into particles within the cylindrical drying zone.

(D) Continuously countercurrently spraying the rest of the detergent slurry directly into the cylindrical drying zone. However, this spray is
At least one level of spray nozzles substantially evenly spaced in a plane horizontally across the cylindrical drying zone so that substantially individual sprays break up into particles within the cylindrical drying chamber. To do.

(However, the only disintegrating particles that enter the low-pressure vortex zone are those that are accidentally carried by the swirling motion of the drying gas.) [Detailed Description of the Invention] By explaining the spray drying tower shown in the drawings, Will show apparatus aspects and method aspects of the invention.

In FIG. 1 (a schematic side sectional view showing a spray-drying tower embodying the present invention), a box 10 shows preparation of a clutcher slurry. It includes any conventional clutching or mixing system and has means 11 for delivering the mixture to a high pressure pump 12. Conventional clutching systems are well known to those of ordinary skill in the art and typically include material storage hoppers, conveyors, scales, clutchers, drop tanks, and the like. For purposes of this invention, a clutcher slurry is about 10-50.
% (Preferably about 20-40%) water and about 50-90% (preferably about 60-80%) solids (all by weight). This solid content consists of the components that make up the desired composition of the granular detergent composition. This solid content contains at least one detergent surfactant or detergent builder (detailed later),
Or contains a mixture thereof. The surfactant can be anionic, nonionic, amphoteric or zwitterionic. Preferably, an anionic surfactant is used. It is common practice to use a mixture of different detergent surfactants and a mixture of different builder substances in forming the slurry.

The slurry is delivered by a high pressure pump 12 through suitable conduits, conduits, etc. (11). Any suitable pump can be used, but is preferably 27-137 atmospheres, preferably 34-1.
It can generate a pressure of 03 atmospheres.

The present invention can be modified and adapted for many things such as channels, but an air injection system is shown at 14. This is a commonly used classical density control system. While this is an optional aspect of the invention, it is a useful device and its use is recommended. The amount of air injected into the system from this supplemental source ranges from 0 to about 1967.
It should be a standard cm ³ / min, preferably about 393-1416 standard cm ³ / min. The air pressure should be at least 3.4 atmospheres higher than the air pressure provided by the high pressure pump.

From this air injection stage, the aerated slurry enters the chamber 39 of the spray drying tower, the supply line 13 to the nozzle arm 15 and the spray nozzle 16, and the supply line 17 to the spray nozzle 18.
To the spray nozzle 20 by the supply line 19 and by the supply line 21 to the nozzle arm 15 and the spray nozzle 22.
To be sent at the same time. Nozzles 16, 18, 20 and 22 may be of any type suitable for spray drying detergent slurries. Preferred is a hollow conical nozzle with an orifice of 0.32-0.7 cm diameter. With such a nozzle, it is usual to obtain a spray having a length of 0.15 to 0.9 m and an angle of 30 to 75 °.

The spray-drying tower includes a spray-drying chamber 39 (with spray nozzles uniformly and spaced inside the spray-drying chamber 39) and a hot air duct 23.
(This is shown as having a hot air inlet hole 25 leading to a plenum 24 for distributing hot air to the chamber 39). The hot air from this arrangement is introduced into the chamber 39 in a swirling motion. For best results, use hot air at about 260-538 ° C, preferably about 316-427 ° C.
The particles obtained by spraying the clutcher slurry countercurrently from the spray nozzle 22 should be flash dried at a temperature of 0 ° C, more preferably about 357-399 ° C. In addition, hot air is introduced into chamber 39 at a velocity of about 15-30 m / sec, preferably about 18-23 m / sec, so that the particles are
It should be possible to obtain the desired swivel motion without hitting the walls of 39 and the cone 26 without crushing. The air pressure inside the chamber 39 and the cone 26 is about 0.0005 to 0.0038 kg / cm.
It is typically in the range of ² (gauge). The swirling motion of the heated drying air is controlled by the nozzles 16, 18, 20 and 22.
It is important that the nozzles are evenly spaced horizontally at each spray level as well as at each vertical level.

At the base of the spray tower is a cone 26 and a transport means 27 for removing dry particles. Dry particles are sieved by the transport means 27.
Sent to. There, the coarse particles 29 are collected and, if necessary, recycled by line 30 to the clutcher slurry 10. The desired product particles 31 are collected and packaged or stored.

A gas discharge means 32 is provided at the top of the spray tower. A line 33 emerges from this outlet to direct the fine particles to a suitable treatment or recovery area 34. From this point, exhaust gas is released into the atmosphere.

Inside the chamber 39 of the spray tower a cylindrical spray drying zone 40 and a swirl zone 38 are shown. The elements of the cylindrical spray-drying zone and the swirl zone 38 are determined by the swirling effect of the rising hot air. In practicing the present invention, it is important that the flat spray from the spray nozzle is disintegrated in this cylindrical drying zone. It has been found that when this condition is fulfilled, production rates are improved, density is controlled, particle size is homogenized, particle stickiness is reduced, dust and coarse particle formation is reduced, and vaporous effluent is obtained. The optimum result is obtained from the viewpoint of reduction of.

The size of the cylindrical vortex zone can be varied by various factors such as the velocity of the heated drying air, the size of the device, etc. It is important to consider the swirl zone that this region has low pressure and temperature, and the particles newly sprayed into this swirl zone are subject to the effects of the optimal drying conditions created by the present invention. It means not. When freshly sprayed particles enter this low pressure concentric swirl zone, they fall through the tower inadequately to dry, which conflicts with the purpose of the invention described above. The vertical and horizontal separation of the nozzles must therefore be defined from this point of view. That is,
The flat spray from each nozzle must collapse within the cylindrical spray zone and not within the swirl zone. Therefore, the expression "directly into the cylindrical spray-drying zone" is used here to indicate the importance of avoiding spraying into the swirl zone.

FIG. 1 also shows another aspect of the invention, namely the vertical spacing of the spray nozzles at several levels,
Is shown. Special consideration should be given to the positioning of the spray nozzle. That is, at least a portion (ie, about 30-100% by weight) of the detergent slurry is co-currently atomized with air in the temperature and velocity ranges indicated herein. This is fundamental to achieving and optimizing the above objectives. In FIG. 1, co-current atomization with air is achieved by the level indicated by feed line 21 and atomizer nozzle 22. Providing at least 30% by weight of slurry to this level of nozzle,
It is necessary to maximize the benefits of the present invention. Amounts of slurry up to 100% can be fed to this level, but only up to about 90% to balance various operating conditions, hot air addition rate, swirl effect, drying rate, etc. It is preferable. It is preferred to deliver about 50-85 wt% slurry to this level of spray nozzle.

When the nozzles are used at two levels, it is desirable that the upper level nozzles be located in the in-column zone at temperatures of about 66-121 ° C.

When using nozzles with more than two levels, the levels should generally be evenly spaced to avoid overlapping sprays.

FIG. 2 is an enlarged sectional view taken along line 2-2 of FIG. 1, showing a cylindrical drying zone, a low pressure concentric spiral zone, and optionally a spray nozzle ( The detergent slurry is countercurrently sprayed with an upward flow of hot air) substantially evenly spaced on a horizontal plane across the cylindrical drying zone. In FIG.
The spray nozzles 16 are arranged substantially uniformly apart.
These nozzles 16 are manifold rings that go to the supply line 13.
Represented as part of 42. Within the tower, it is important that the spray nozzles are positioned and oriented such that the spray is not too close to the chamber wall 39 or the low pressure swirl zone 38. When the freshly sprayed slurry touches the wall 39, the slurry may tend to adhere to the wall and form large deposits. Such deposits are difficult to remove and can interfere with the desired flow of gas intended by the method and apparatus of the present invention.

FIG. 3 is an enlarged cross-sectional view taken along line 3-3 of FIG. 1 with additional desired spray nozzles (spray countercurrent with hot air) below that of FIG. At substantially the same level on a horizontal plane across the cylindrical drying zone. In FIG. 3, the spray nozzles 20 are substantially evenly spaced apart. These nozzles
Twenty is shown as attached to a nozzle arm 15 attached to a manifold ring 44 going to supply line 19. As mentioned above, it is important to space and orient the spray nozzles within the tower such that the spray is not too close to the chamber wall 39 or the low pressure swirl zone 38.

In FIG. 3, the plenum is shown at 24.

4 is an enlarged cross-sectional view taken along line 4-4 of FIG. 1 where the spray nozzle (spraying detergent slurry countercurrently with hot inlet air) traverses the cylindrical drying zone. It is explained that they are substantially evenly spaced on a horizontal plane. In this case, the nozzle is located at the lowest level of the spray tower. In Figure 4, the spray nozzles 22 are substantially evenly spaced. These nozzles are shown mounted on the nozzle arm 15 and
15 is attached to a manifold ring 44 outside the air chamber 24 and leading to the supply line 21. The nozzle arm 15 passes through the hot air inlet hole 25 in the air chamber 24 so that the nozzle 22 is located inside the tower chamber 39. Nozzle 22 is about 2.5c in chamber 39
Place it somewhere between the inside and about 30 cm outside,
The slurry may be atomized at the desired air temperature and velocity. Again, in the tower, the spray nozzles are sprayed onto the chamber wall 39 or in a low pressure vortex zone.
It is important to set the spacing and orientation so that they are not too close to 38. Preferably, the nozzle arm 15 includes
A nozzle sleeve (not shown) is added to protect it from the high temperatures of the inlet air as it passes through the air chamber 24.

<Detergent Composition> In the present invention, various compositions of detergent composition can be prepared.

Detergent surfactants are well known anionic, nonionic,
It can be chosen from the class of amphoteric and zwitterionic detergent surfactants. Mixtures of surfactants can also be used here. More specifically, U.S. Pat.
7,630 (Booth, dated February 20, 1973) and U.S. Pat. No. 3,332,880 (Kessler et al., July 25, 1967).
The surfactants indicated in (Dating) can be used in the present invention (both of which are incorporated herein by reference). Specific examples of detergents suitable for use in the compositions of the present invention are set forth below for purposes of illustration and not limitation.

Water-soluble salts of higher fatty acids or soaps are useful anionic surfactants in the present invention. This includes alkali metal soaps such as sodium, potassium, ammonium and alkanol ammonium salts of higher fatty acids having about 8 to about 24 carbon atoms, preferably about 12 to about 18 carbon atoms.
There is. Soap can be made by direct saponification of fats or oils or by neutralization of free fatty acids. Particularly useful are the sodium and potassium soaps of fatty acid mixtures obtained from coconut oil and tallow, ie sodium or potassium tallow and coconut soap.

Useful anionic surfactants are organic sulfuric acid reaction products containing an alkyl group having about 10 to about 20 carbon atoms and a sulfonic acid or sulfate ester group in the molecular structure (the "alkyl group" includes an alkyl portion of an acyl group). There is also. Examples of synthetic surfactants in this group are those obtained by sulfation of sodium or potassium alkylsulfates, especially higher alcohols (8 to 18 carbon atoms) (for example those obtained by reduction of glycerides of tallow or coconut oil). , And linear or branched alkyl (having about 9 to about 9 carbon atoms).
About 15) benzene sulfonates (sodium and potassium), such as US Pat. Nos. 2,220,099 and 2,477,3
There are those of the type described in U.S. Pat. No. 83, of particular value are linear alkyl benzene sulphonates having an average alkyl group carbon number of about 11 to 13, i.e. C
_{11-13 It} is abbreviated as LAS.

Other anionic surfactants are (a) alkyl glyceryl ether sulfonates (sodium), especially ethers of higher alcohols from tallow and coconut oil, (b)
Coconut oil fatty acid monoglyceride sulfonate and sulphate (sodium), (c) alkylphenol ethylene oxide ether sulphate (sodium or potassium) having about 1 to about 10 units of ethylene oxide per molecule and having about 8 to about 10 carbon atoms in the alkyl group.
12 and (d) alkyl ethylene oxide ether sulfates (sodium or potassium) having from about 1 to about 10 units of ethylene oxide per molecule and having an alkyl group of from about 10 to about 20 carbon atoms. is there.

Other useful anionic surfactants are (a) water-soluble salts of esters of alpha-sulfonated fatty acids, wherein the fatty acid group has about 6 to 20 carbon atoms and the ester group has about 1 to 10 carbon atoms.
A water-soluble salt of 2-acyloxyalkane-1-sulfonic acid having an acyl group having about 2 to 9 carbon atoms and an alkane moiety having about 9 to 23 carbon atoms, (c) olefin and paraffin sulfonate A water-soluble salt with about 12 to 20 carbon atoms
And (d) beta alkyloxy alkane sulfonates having an alkyl group having about 1 to 3 carbon atoms and an alkane moiety having about 8 to 20 carbon atoms.

Preferred anionic surfactants are C _{11 to} C ₁₃ linear alkyl benzene sulfonates, C _{10 to} C ₁₈ alkyl sulphates, and ethoxylates of C _{10 to} C ₁₈ alkyl sulphates (about 1 to about 6 ethylene oxide per mole of alkyl sulphate). Mol) and mixtures thereof.

Water soluble nonionic surfactants are also useful in the present invention. Such nonionics are those obtained by condensing alkylene oxide groups, whose properties are hydrophilic, with organic hydrophobic compounds, which can be aliphatic or alkylaromatic. There is. The length of the polyalkylene group condensed with a particular hydrophobic group can be easily adjusted to obtain a water-soluble compound having the desired hydrophilic / hydrophobic balance.

Suitable nonionic surfactants include polyalkylene oxide condensates of alkylphenols, such as alkylphenols having straight or branched chain alkyl groups of about 6 to 15 carbon atoms and about 3 to 12 per mole of alkylphenol.
There is a condensate of moles of ethylene oxide.

Preferred nonionic surfactants are water-soluble and water-dispersible condensates of straight or branched chain aliphatic alcohols having 8 to 22 carbon atoms and 3 to 12 mol of ethylene oxide per mol of alcohol. Particularly preferred are alcohols having an alkyl group of about 9 to 15 carbon atoms and alcohol 1.
It is a condensate with about 4 to 8 mol of ethylene oxide per mol.

The semipolar nonionic surfactant has (a) about 10 carbon atoms.
Water-soluble amine oxide containing one alkyl moiety having 18 to 18 carbon atoms and two moieties selected from the group consisting of alkyl groups having 1 to 3 carbon atoms and hydroxyalkyl groups, (b)
A water-soluble phosphine oxide containing one alkyl moiety having about 10 to 18 carbon atoms and two moieties selected from the group consisting of an alkyl group having about 1 to 3 carbon atoms and a hydroxyalkyl group, and (c) about 10 to about carbon atoms. There are water soluble sulfoxides containing one 18 alkyl moieties and moieties selected from the group consisting of alkyl groups of about 1 to about 3 carbon atoms and hydroxyalkyl groups.

Zwitterionic surfactants include derivatives of aliphatic quaternary ammonium, phosphonium and sulfonium compounds in which one of the aliphatic substituents has about 8-18 carbon atoms,
There is.

The detergent composition generally comprises from about 5% to about 80%, preferably about
10 to about 60%, more preferably about 15 to about 50% (by weight),
Of the spray-dried detergent composition.

In addition to detergent surfactants, detergency builders can be used in the final granular detergent product. Water soluble inorganic or organic electrolytes are suitable builders. The builder
It can also be a water-insoluble calcium ion exchange material. Non-limiting examples of suitable water-soluble inorganic detersive builders are alkali metal salts of carbonic acid, boric acid, phosphoric acid, bicarbonate and silicic acid. Specific examples of such salts include the sodium and potassium salts of tetraboric acid, bicarbonate, carbonic acid, orthophosphoric acid, pyrophosphoric acid, tripolyphosphoric acid and metaphosphoric acid.

Suitable organic alkaline detersive builders include (1) water-soluble aminocarboxylates and aminopolyacetates such as nitrilotriacetate, glycinate, ethylenediaminetetraacetate, N- (2-hydroxyethyl) nitrilodiacetate and diethylenetriaminepentaacetate. (2) Water-soluble salts of phytic acid, such as potassium phytate, (3) Water-soluble polyphosphates, such as ethane-1-hydroxy-1,
Sodium, potassium and lithium salts of 1-diphosphonic acid, sodium, potassium and lithium salts of ethylenediphosphonic acid, etc. (4) Water-soluble polycarboxylates such as lactic acid, succinic acid, malonic acid, maleic acid, citric acid, Oxydisuccinic acid, carboxymethyloxysuccinic acid, 2-oxa-1,1,3-propanetricarboxylic acid, 1,1,2,2-ethanetetracarboxylic acid, salts of mellitic acid and pyromellitic acid, (5) US Pat. 4,144,266
And water-soluble polyacetals disclosed in US Pat. No. 4,246,495 (incorporated herein by reference), and (6) US Pat. No. 4,663,071 (Bush).
Et al., May 5, 1987) (incorporated herein by reference), water soluble tartarate monosuccinates and disuccinates and mixtures thereof,
There is.

Another type of detersive builder useful in the final particulate detergent product is one that consists of a water soluble material that can react with water hardness cations to form water insolubility. here,
The reaction with water hardness cations is preferably carried out in combination with crystalline seeds capable of providing growth sites for this reaction product, but such "seed builder" compositions are described in detail in GB 1,424,406. It is disclosed.

Another class of detersive builder materials useful in the present invention is the insoluble sodium aluminosilicate represented by the formula below, disclosed among others in Belgian Patent No. 814,874 (November 12, 1974). It is

Na _z- (AlO ₂ )-(SiO ₂ ) _y XH ₂ O (where z and y are integers of at least 6, the molar ratio of z to y is 1.0: 1 to about 0.5: 1, X is about 15 to This is an integer of about 264.) The aluminosilicate has a calcium ion exchange capacity of at least 200 mg equivalent / g and a calcium ion exchange rate of at least about 2 grains / gallon / min / g. Preferred materials is a zeolite A, which is Na ₁₂ - is a _{(SiO 2 AlO 2) 12 27H} 2 O.

Preferably, the builder comprises tripolyphosphate, pyrophosphate, carbonate, polycarboxylate, or aluminosilicate detersive builder or mixtures thereof.

The detersive builder component generally comprises about 10-90%, preferably about 15-75%, particularly preferably about 20-60% (by weight) of the spray dried detergent composition.

Optional ingredients that can be included in the granular detergents of the present invention include cationic surfactants, softeners, enzymes (eg, proteases and amylases), bleaches and bleach activators, soil release agents, soil suspension agents, fabrics.・ Brightener, enzyme stabilizer, color speckle, foam enhancer and foam suppressor, anticorrosive, colorant, filler, bactericide, pH
Substances like regulators, non-builder alkalinity sources, etc. Those materials which are heat sensitive or which are modified by other materials in the clutcher mix slurry are generally mixed with the spray dried portion of the final granular detergent composition.

The following examples are intended to illustrate the compositions, methods and devices of this invention without intending to be limiting.

All parts, percentages and ratios are by weight unless otherwise stated.

Example I A granular detergent composition of the present invention containing the following ingredients is prepared. Ingredient % by weight C ₁₂ Sodium alkylbenzene sulfonate 4.1 C _14-15 Sodium alkyl sulfate 6.4 Sodium tallow alkyl sulfate 6.4 C _12-13 Alcohol polyethoxylate (6.5) 0.5 Sodium tripolyphosphate 39.3 Sodium carbonate 12.3 Sodium silicate solid 5.6 Polyethylene glycol ( MW8000) 0.5 Protease enzyme 0.5 Sodium sulfate 15.3 Water and minor components Approximately 30% residual water and approximately 70% of the above components (excluding alcohol polyethoxylate surfactant, enzymes and other minor components) The slurry is spray dried in a spray drying tower with a diameter of 6.4 m as shown in FIG. The spray nozzle is about 2.4 m, about 6.7 m, about 10.7 m or about 16.8 m from the tower top.
Are spaced substantially uniformly over one or more of the horizontal planes. In this example, two nozzles are located at the first or top level, no nozzles at the second level and four nozzles at the third level and a fourth or Five nozzles are located at the lowest level (such a nozzle arrangement is
Hereinafter referred to as 2-0-4-5). All of the nozzles are substantially evenly spaced on a horizontal plane within the drying zone. Spray approximately the same amount of slurry from each spray nozzle.
Therefore, about 45% of the slurry is sprayed from the lowest nozzle. As shown in Fig. 1, the slurry is at the lowest level nozzle, air (temperature about 292 ℃, flow rate about 20.8m
/ Sec) and is sprayed directly into the cylindrical drying zone at the bottom of the drying tower. About 18% of the slurry is atomized countercurrently with rising air at about 2.4 m from the tower top. About 36% of the slurry is atomized countercurrently with rising air at about 10.7 m from the top of the tower. Substantially each of the sprays collapses in the cylindrical drying zone into particles, and the only disintegrating particles entering the low pressure swirl zone in the tower are those accidentally carried by the swirling motion of the drying gas. The spray-dried particles are collected, the enzyme and other minor components are mixed, and the alcohol polyethoxylate surfactant is sprayed to control dusting to obtain a finished granular detergent composition.

The resulting spray-dried granular detergent composition is crunchy, free-flowing, with uniform particles, good solubility, reduced solidification, and reduced phosphate conversion.

Other methods and compositions of the present invention are described in the above example nozzle arrangements 2-0-0-5, 2-0-2-4, 2-0-4-.
5, 2-0-0-11, 2-0-2-7, 2-0-2-9,
2-0-2-10, 2-0-2-13, 1-0-0-13 and 0-
It is obtained by modifying by using 0-2-13 as well as using an inlet air temperature of 233-328 ° C.

Other methods and compositions of the present invention are described in the above example nozzle arrangements 0-0-0-15, 4-2-4-5, 4-0-4-12, 2
Obtained by modification by the use of −0-10-20 and 2-0-6-15 and the use of inlet air velocity 15.2-30.4 m / sec.

Example II A granular detergent composition is prepared containing the following ingredients. Ingredients % by weight C ₁₂ Sodium linear alkylbenzene sulfonate 4.1 Sodium tallow alkyl sulphate 6.4 C _14-15 Sodium alkyl sulphate 6.4 C _12-13 Alcohol polyethoxylate (6.5) 0.5 Sodium toluene sulfonate 1.0 Sodium tripolyphosphate 5.6 Tetrasodium pyrophosphate 22.4 Sodium Carbonate 12.3 Sodium Silicate Solids 5.6 Sodium Polyacrylate (MW4500) 1.2 Polyethylene Glycol (MW8000) 0.5 Protease Enzyme 0.3 Sodium Sulfate 29.8 Water and Minor Components Residual composition as described in Example I, nozzle placement 2- 0-
4-5, 2-0-0-10 and 2-0-0-7 and an inlet air temperature of 341-362 [deg.] C. and a flow rate of about 20.8 m / sec.

Example III A granular detergent composition is prepared containing the following ingredients. Ingredient Weight% C ₁₃ Sodium linear alkylbenzene sulfonate 10.8 C _14-16 Sodium alkyl sulphate 11.3 Tallow fatty acid 2.2 C _12-13 Alcohol polyethoxylate (6.5) 1.1 Solite A sodium (hydrate, average particle size 3 microns) 27.9 Sodium silicate solid 2.4 Sodium carbonate 16.4 Sodium polyacrylate (MW4500) 3.4 Polyethylene glycol (MW8000) 1.1 Protease enzyme 0.4 Sodium sulphate 14.7 Water and minor ingredients Residual composition was nozzle set 2-0 as described in Example I. −
2-4 and 2-0-0-8 and inlet air temperature 309
At -322 ° C and a flow rate of about 20.8 m / sec, a composition of the invention is obtained.

[Brief description of the drawings]

FIG. 1 is a schematic side sectional view showing a spray-drying tower embodying the present invention. FIG. 2 is an explanatory view showing an enlarged sectional view taken along line 2-2 of FIG. FIG. 3 is an explanatory view showing an enlarged sectional view taken along line 3-3 of FIG. FIG. 4 is an explanatory view showing an enlarged cross-sectional view taken along the line 4-4 in FIG.

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Claims (18)

(57) [Claims] 1. A large volume detergent slurry is spray-dried in a spray-drying tower comprising the steps (a)-(d) below to obtain a controlled-density granular detergent composition to form dust particles and other particles. A continuous process that produces with minimal vapor effluent formation. (A) An aqueous detergent slurry having from about 10 to 50% by weight of water and about 50 to 90% by weight of solids comprising at least one detergent surfactant or detersive builder or mixtures thereof. To prepare. (B) The heated drying air is swirled upward in the chamber of the spray-drying tower to form a cylindrical drying zone (a) coaxial with the chamber, and Forming a low pressure concentric vortex zone (B) formed along an axis. (C) About 30-100% by weight of the detergent slurry is continuously and directly co-flowed with air having a temperature of about 260 ° -540 ° C. and a flow rate of about 15-30 m / sec directly into a cylindrical drying zone. To spray. However, the spraying is performed by spray nozzles that are substantially evenly spaced on a plane that horizontally traverses the drying zone,
Disintegrating substantially individual sprays into particles within the cylindrical drying zone. (D) Continuously countercurrently spraying the rest of the detergent slurry directly into the cylindrical drying zone. However, this spray is
At least one level of spray nozzles substantially evenly spaced in a plane horizontally across the cylindrical drying zone so that substantially individual sprays break up into particles within the cylindrical drying chamber. To do. (However, the only disintegrating particles that enter the low-pressure vortex zone are those that are accidentally carried by the swirling motion of the drying gas.) 2. The method of claim 1 wherein the co-current atomization is effected by atomizing nozzles which are substantially evenly spaced on a horizontal plane near the bottom of the hot air inlet holes. 3. The method of claim 1 wherein in step (c) the amount co-currently sprayed with air is about 50-85% by weight of the detergent slurry. 4. In step (d), a portion of the detergent slurry is provided by at least one level of uniformly spaced spray nozzles located at a high level in the tower at a temperature of about 66 to about 121 ° C. The method of claim 1, wherein the cylindrical drying zone is convectively sprayed. 5. In step (c), the air has a temperature of about 35.
The method according to claim 4, which has a flow rate of about 17.8 to 22.9 m / sec at 7 to 399 ° C. 6. Detergent slurry is about 20-40% by weight.
2. The method of claim 1 comprising at least 60% to about 80% of water and a mixture of at least one detergent surfactant and at least one detersive builder. 7. The method of claim 6, wherein the detergent surfactant comprises an anionic surfactant. 8. The method of claim 7, wherein the detersive builder comprises a tripolyphosphate, pyrophosphate, carbonate, polycarboxylate or aluminosilicate detersive builder, or mixtures thereof. 9. In step (c), the amount co-currently sprayed with air is about 50-85% by weight of the detergent slurry,
9. The method of claim 8 wherein the co-current atomization is effected by atomizing nozzles that are substantially evenly spaced on a horizontal plane near the bottom of the hot air inlet holes. 10. The anionic surfactant is C _11-13 linear alkylbenzene sulfonate, C _10-18 alkyl sulfate, and about 1 to about 6 moles of ethylene oxide per mole of alkyl sulfate of C _10-18 alkyl sulfate. 10. The method of claim 9 selected from the group consisting of ethoxylates according to, and mixtures thereof. 11. A controlled-density, high-volume granular detergent composition having a combination of the following components (a)-(g) is produced while minimizing the production of dust particles and other vaporous effluents. Spray drying tower for. (A) Spray drying chamber. (B) Means for introducing and maintaining the heated swirl flow of the drying gas into the spray drying chamber (a). However, this swirling motion is substantially coaxial with the spray drying chamber (a) in the longitudinal direction, and the cylindrical drying zone coaxial with the axis of the chamber (a) and the axis of the chamber (a). To form a low pressure concentric vortex zone along. (C) Means for venting gas from the top of the spray drying chamber (a). (D) having about 10-50% by weight of water and about 50-90% solids, the solids comprising at least one detergent surfactant or detersive builder or mixtures thereof. Means for providing an aqueous detergent slurry. (E) About 30 to 100% by weight of the detergent slurry in cocurrent with air having a temperature of about 260 to 538 ° C. and a flow rate of about 15.2 to 30.4 m / sec.
Means for direct continuous spraying of the above into the cylindrical drying zone directly. However, the spraying is carried out by means of spray nozzles which are arranged substantially evenly spaced on a horizontal plane across the cylindrical drying zone, so that substantially each of the spray products is disintegrated in said cylindrical drying zone. To make particles. (F) A means for continuously spraying the remainder of the detergent slurry directly countercurrently into the cylindrical drying zone at a level higher than the level of co-current spraying in (e) above.
However, the counter-current spraying is performed by at least one level of spray nozzles which are substantially evenly spaced apart on a horizontal plane across the cylindrical drying zone, so that substantially each of the sprays is It is disintegrated into particles in a cylindrical drying zone. (However, the only disintegrating particles that enter the low-pressure vortex zone are those that are accidentally carried by the swirling motion of the drying gas.) (G) The dried particles are discharged from the bottom of the spray drying chamber (a). Means for taking out. 12. The spray drying tower according to claim 11, wherein the horizontal level of the spray nozzle of (e) is located near the tower bottom of the hot air inlet hole. 13. (f) having at least a second level of uniformly distributed spray nozzles for countercurrent spraying.
12. The spray drying tower according to 12. 14. A spray-dried granular detergent composition made by the method of claim 1. 15. About 5 made by the method of claim 5.
A spray dried particulate detergent composition comprising from about 80% to about 80% detergent surfactant and from about 10% to about 90% detersive builder. 16. The method according to claim 10, which is about 10
A spray dried particulate detergent composition comprising from about 60% to about 60% detergent surfactant and from about 15% to about 75% detersive builder. 17. A C _{11 produced} by the method of claim 16.
To C ₁₃ linear alkyl benzene sulphonate, C _10-18 alkyl sulphate and ethoxylates with about 1 to about 6 moles of ethylene oxide per mole of alkyl sulphate of C _10-18 alkyl sulphate, and mixtures thereof. A spray-dried granular detergent composition comprising an anionic surfactant. 18. A spray produced by the method of claim 17, wherein the detersive builder comprises a tripolyphosphate, a pyrolenate, a carbonate, a polycarboxylate, or an aluminosilicate detersive builder, or a mixture thereof. Dry granular detergent composition.